Electrical contact maker and breaker



jan. 19 ,1926.

ELECTRICAL CONTACT MAKER AND BREAKER Filed June 20, 1924 may/(Man Commufmor Patented Jan. 19, 1926.

UNITED STATES PATENT OFFICE.

VICTOR YNG-VE, OF SOUTH ORANGE,-NEW JERSEY, ASSIGNOR T MANHATTAN ELEC- TRICAL SUPPLY COMPANY, INCORPORATED,

TION OF MASSACHUSETTS.

OF NEW YORK, N. Y., A CORPORA- ELECTRICALCONTACT MAKER'AN D BREAKER.

Application filed J'une 20,1924. Serial No. 721,353.

To all whom it may concern:

Be it known that I, VICTOR YNGVE, citizen of the United States, residing at South Orange, in the county of Essex and State of New Jersey, United States of America, have invented certain new and useful Improvements in ElectricalOontact Makers and Breakers, of which the following is a specification.

This invention relates to improvements in electrical contact makers and breakers, and more particularly to a new commutator adapted for use in circuits of electrical motors and the like.

1 In accordance with the present invention, the contact points of a circuit maker and ln-cakor or the contacting surface of a commutator, is covered with a thin coating of metallic chromium. Preferably, the Working surfaces of the contact points or commutalors of copper, bronze or the like, are electroplated with chromium, best results being obtained by using Sargents solution of 245 gr/L chromic acid and 3 g/L chromium sulha-tc. and a current densityof 13.4 amp/sq.

dm. (125 amp. sq. ft.), using a chromium anode.

GlllOll'lllll'll is exceedingly hard and holds a bright, silver-like lustre almost indefinitely. l nrthermore, chromium resists corrosion. Owing: to its resistance to corrosion and its hardness, a chromium surface is preferable, for the present purposes, to a copper surface. While the electrical c0nductivity of chromium is only about onefifth that of copper, this is not an impediment to its use in commutators or the like, because, in accordance with the present invention, the circuit controller is coated with a very thin layer (e. g., .005 of an inch) of a metallic chromium. The relatively high resistance offered by this thin layer is negligible as compared with the advantages obtained from its resistance to wear and corrosion.

The drawing illustrates'in vertical crosssection a commutator, the contacting surface of which is electroplated with metallic chromium.

\Vhat I claim is: i

1. .An electrical circuit controller coated with metallic chromium.

2. An electrical circuit maker and breaker, electroplated with a coating of metallic .chromium.

3. An electrical circuit maker and breaker, the contacting surface of which is electroplated with a coating of metallic chromium of a thickness of inch.

4. A commutator having on its contacting surface an electrolytically deposited lay- June, 1024.

. VICTOR YNGVE.

about .005 of an .er of chromium of a thickness of about .005 p 

